Field of the Invention
The present invention relates to a compressing device.
Description of the Related Art
There has been known a compressing device that recovers heat energy of a compressed gas discharged from a compressor. For example, JP 2011-012659A discloses a compressor that includes a compressor body, a heat exchanger for exchanging heat between a compressed air discharged from the compressor body and a working fluid, an expander for expanding the working fluid flowing out of the heat exchanger, a generator connected to the expander, a condenser for condensing the working fluid flowing out of the expander, and a circulation pump for sending the working fluid flowing out of the condenser to the heat exchanger. In this compressor, the heat energy received by the working fluid from the compressed air in the heat exchanger is recovered in the expander and the generator, and, on the one hand, the compressed air is supplied to an outside after being cooled by the working fluid in the heat exchanger.
In the compressor described in JP 2011-012659 A above, when the expander is stopped in operation at the time of maintenance of the expander or the like, the working fluid is unable to circulate in a flow channel connecting the heat exchanger and the expander, and the compressed air is not sufficiently cooled by the working fluid in the heat exchanger. This results in raising a possibility of suspending operation of the compressor as well.
Similarly, when the expander is rotated at a low speed, the working fluid is unable to sufficiently circulate in the flow channel, thus the compressed air is not sufficiently cooled in the heat exchanger.
The present invention has been made in view of the aforementioned problems, and has an object to perform cooling of a compressed gas by a working medium in a heat exchanger regardless of operation conditions of an expander.